Stay-cord guide for buttonhole-sewing machines



March 23 1926. 1,577,601

E. B. ALLEN STAY CORD GUIDE FOR BUTTONHOLE SEWING MACHINES Filed April 8, 1925 3 Sheets-Sheet 1 jmil l-i INVENTOR w|TNEs5 BY A ORNEY March 23 1926.

E. B. ALLEN STAY CORD GUIDE FOR BUTTONHOLE SEWING MACHINES Filed April 8, 1925 I5 Sheets-Shasta INVENTOR 57% ATTORNEY WITNES ES E. B. ALLEN STAY CORD GUIDE FOR BUTTONHOLE SEWING MACHINES Mam}: 23 1926.

Filed April 8, 1925 5 Sheets-Sheet 3 INVENTOR WITNESSE ATTORNEY Patented Mar. 23, 1926.

- unites stares masters COPY 1,577,501 PA'ENT r es.

EDWARD B. ALLEN, OF NEVITOHN, CONNECTICUT, ASS lGNOR TO THE SING-ER FACTURING COMPANY, OF ELIZABETH, HEX JERSEY, .A-CORPOB/ATION OF NEW JERSEY.

STAY-C'QRD GUIDE role BUTTONI-IOLE-SEWING MACHINES.

Application filed April 8, 1925. Serial No. 21,468.

To all whom it may concern: 7

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at l\ ewtown, in the county of Fairficld and State of Connecticut, have invented certain newand useful Improvements in Stay-Cord Guides for Buttonhole-Sewing lilachines, of which the following is a specification, reference being had thereinto the accon'ipanying drawings. V

This invention relates to machines of the buttonholesewing type and has for an object to provide a machine oi'this nature with an improved stay-cord guiding mechanism which will, at all stages of the sewing, accurately, deliver the stay-cord within the range of action of the over-seaming stitchforming mechanism and maintain a uniform lateral position of the stay-cord within the oversear'n, thereby i 'isuring not only the complete covering of the stay-cord but. also a uniform appearance of the purl, even in cases where the stitclrforming mechanism is designed or adjusted to sew a, narrow overseam or an overseam in which the stitches are slanted at an acute angle to the direction of seam-formation.

Heretofore, it has been the usual practice 3 buttonhole .sewing machine with a stay-cord guiding aperture fixed in position relative to the needle-throat member and the needle paths. Difliculty has been experienced with machines having such. relatively fixed needle-throat. and cord-gui ding elements, in obtaining uniformly acceptable work, due to the changes in the direction of seam-formation in sewing about a buttonhole. It has been discovered that if the cord-guiding aperture is so located as to properly direct the cord relative to the needle-paths when sewing the straight side of a buttonhole, it may not be directed to the best advantage when sewing around the eye or at otherbendsin the overseam.

It has also'been observed that when any known machine is used to sew a narrow bight buttonhole, there is difficulty in effooting thecomplete covering of the staycord; there being a tendency for'the bare stay-cord to show" uncovered at one place or another around the buttonhole.

Still further, when any known machine is used to sew a buttonhole with the stitches to provide the needle-throat member of a disposed at an acute angle to the buttonholeslit it has been observed that there is a marked difference in the appearance of the sewing along the two sides of the buttonhole, there being usually a Hat purl eii'ect at one side of the buttonhole and a pyramid purl. effect at the other side or the buttonhole; This difference of appearance seems to be due to the fact that when sewing down one side .ofthe buttonhole, the usual cordguide delivers the cord'clo'se to the depthstitch needle-path, avliile in sewing down the return side of the buttonhole the cord is delivered more nearly, midway between the depthand slit-stitch needle-paths.

According to the present improvement provision is made formoving the stay-cord guide laterally of the direction of seam-formation, to shift its position during the sewing and compensate for changes in the direction' of seam-formation in sewing around a buttonhole; thereby insuring the complete covering ofthe stay-cord and a desirable uniformity in the appearance of" the purl atthe sides of the buttonhole. Y

' In the accompanying drawings, Fig. 1 is a fragmentary perspective view of a buttonhole sewing machine embodying the invention. Fig. 2 is a top plan view of the turret and under stitch-forming devices. Fig. 8 is a front elevation of the turretand under stitch-forming devices. Fig. MS a bottom plan view'ot the feed-wheel. Fig; 5 is an enlarged sectional view on the line55,

Fig. 2. Fig. 6 is a sectional view on the line 6+6, Fig. 3. Fig. 7 is a front elevation of the needle-throat member of the machine. Fig. 8 is a development of the staycord-guide controlling cam. Fig. 9 is a bottom plan view of the needle-throat and staycord guiding members in their relative positions when sewing along the first side of a buttonhole. "Fig. 10 is a similar view when sewing around the eye-end of the buttonhole. Fig. 11 a similar view when sewing down the return side of thebuttonhole. Fig. 12' a similar view when sewing a square bar. across the 'end ofthe'buttom loo hole, and Figs. 13 and l l are similar views p showihg the relation of the stay-cord tothe needle-paths iii n'iachines of the prior ,art

"1 '-1:- n1 L: when sewing along the first and return sides, respectively, of a buttonhde.

For the purposes of the present disclosure the invention will be described as embodied in a buttonhole sewing machine constructed substantially in accordance with the disclosure of my copending application Serial No. 742,507, filed October 9, 1924. This machine has the usual frame including the bed 1, standard 2, overhanging arm 3 and head a. The stitch-forming, mechanism comprises the upper reciprocating and lat erally jogging needle 5 which cooperates with the usual loop-taking devices 6, 7, car ried by the rotary turret 8. The needle and turret are turned about a common vertical axis coincident with the center line of the turret bearing-aperture 8, Fig. 3, by the usual pinion and sector gear connections 9, 9, Fig. 1, with the links 10, 10 and arms 11, 1.1 secured to the vertical shaft 12; the lower arm 11 having the usual cam-follower 13 entering the stitch-forming-mechanism-rotating cam-groove 14- in the feed-wheel 15.

The machine also comprises the usual work-holder including lower worksupporting plates and upper clamping feet, one of each of which is shown at 16 and 17, respectively, in Fig. 1.

Relative movement between the stitchforming mechanism and work-holder to carry the sewing about the buttonhole is effected by giving the work-holder the usual longitudinal and side-shift movements by suitable connections (not shown) with the longitudinal and lateral feed-cam grooves 18, 19, respectively, in the feed-wheel 15.

The turret has fixedly mounted thereon in the usual manner the needle-throat member 20, the front or free end of which is, however, in the present instance, cut off to form a plane face 21 in engagement with which the present novel stay-cord guide 22 works in close proximity to the paths of the jogging needle 5. The needle-throat member 20, Figs. 6, 7 and 9, has the usual heartshaped needle-aperture 23 in advance of which the member 20 is formed with a widened stay-cord clearance passageway 24.

The stay-eord guide 22 is formed with a guiding aperture 25 for the stay-cord s, Fig. 9, and is preferably constructed in the form of a bent lever 26, Fig. 3, which may conveniently be pivotally mounted at 27 on the post 27 rising from the turret 8. The lever 26 includes the horizontally disposed arm 28 formed with the vertical slot 29, Fig. 5, through which passes the screw 30 threaded into the vertically adjustable carrier 31 for the follower'roll 32 which rides upon the stationary circular cam-track 33 concentric with theturret axis. It will be readily understood that, as the turret turns, the cordguiding lever 26 will be rocked about its fulcrum 27 to shift the cord-guiding aperture 25 laterally of the direction of seamformation or parallel to the plane of vibration of the needle 5; the lateral position of the cord-guiding aperture 25 at any time being determined by the elevation of the particular portion of the cam track 33 directly under the follower roll 32. The spring 34, Fig. 3, maintains the roll 32 constantly in engagement with the cam-track 33.

When the machine is at rest the turret 8 occupies the position shown in Fig. 2 relative to the direction 0 of seam-formation along the first side of the buttonhole-slit. The cam-follower 32 is located at 32, Fig. 8,

and the stitch-rotating cam-follower occupies full line position 13 Fig. 4, relative to the cam-groove 14 in the feed-wheel 15. hen the machine is started, the feedwheel is given a rapid movement through an angle a to carry the work-holder to sewing position. During this rapid feed of the workholder the feed-wheel is turned sutliciently to shift the follower 13 to the position 13", Fig. 4-, thereby turning the turret about 30 in a eounter-clockwise direction from the position shown in Fig. 2 to that shown in Fig. 9. This is done to place the plane a :0, Fig. 9, of vibration of the needle 5 on a slant or at an angle G to the direction of seam-formation so that the stitches will be inclined to the buttonhole-slit and give a narrow effect to the overseam. During this reverse rotation of the turret, the followerroll 32 of the stay-cord guide is carried from the position 32, Fig. 8, to the position 32", where it remains during the sewing of the first side of the buttonholeand causes the cord-guiding aperture 25 to be disposed in the lateral position shown in Fig. 9, so that the cord will be delivered close to the needle 5 on the depth-stitch thrust of the latter.

When the sewing reaches the eye, the turret is turned to place the stitches substantially radially of the eye. During this turning of the turret the follower roll 32 is shifted from the position 32", Fig. 8, to the position 32, the portion of the cam 33 between these points serving to so shift the cord-guiding aperture 25 as to accurately direct the cord close to the depth-stitch thrust of the needle at all stages of the eye-sewing operation. During the early stages of experimentation, the cam 33 was given a. steady rise from the point 32 to the point 32", but it was found desirable to provide a shallow dip m in the cam to overcome a tendency for the cord to escape being covered by the overseam. The location and magnitude of this dip, if required, will be apparent to one skilled in the art from observation of a stitched buttonhole.

.During the eye-stitching operation, the portion of the cam-slot 14 in the feed-wheel within the angle d acts upon the follower 13 to turn the stitch-forming mechanism including the turret 8.

As the sewing proceeds down the return causes the stay-cord guide 22 to occupy full line position, Fig. 11, to direct the-cord 8 close to the de 'ith-stitch punctures of the The position which the guide 22 needle 5. occupied relative t the needle-throat member 20 in sewing the first side of the buttonhole is shown in dotted linesin. Fig. 11 for purpo 'es of comparison to show the amount of the lateral shift of the stay-cord guide between the first and second side stitching operations.

When the sewing reaches the end the second side of the buttonhole the turret is given a quick turn of about preparatory to sewing the square bar, Fig. 12; This is effected by the portion of the cam-slot 14 within the angle 6. During this turn of the turret the roll 32 is shifted from the position 32", Fig. 8, to the position 32 thereby causing a shift of the cord-guide 22 about halfway back toward the position shown in Fig. 9, or to substantially the same position relative to the needle-throat 20, as shown in Fig. 10. This position of the cord-guide 22, Fig. 12, directs the cord close to the depth-stitch needle-punctures during the sewing of the square bar.

Fig. 13 shows the condition that would obtain were the usual needle-throat member used to sew a buttonhole such as described. The disposition of the needle-throat member 35 at an angle to the buttonhole-slit so shifts the usual relatively fixed cord-guid ing aperture 36 as to cause the cord 37 to be directed so nearly under the point of the needle in its depth-stitch thrust as to endanger puncturing of the cord. When sewing down the return side of the buttonhole the reversely inclined position of the needle throat causes the cord-guiding aperture 36 to direct the cord about midway between the depthand slit-stitch needle-punctures. This would produce a pyramid purl effect along the second side of the buttonhole. That is, the purl would be formed substantially on top of the cord and the appearance of the sewing along the second side of the buttonhole would contrast unfavorably with that along the first side of the buttonhole if, indeed, the cord be covered by 'the firstside stitches. By virtue of the present improvement the cord is uniformly directed in the same relation to the depth-stitch needlepunctures all around the buttonhole, regardless of the style or characteristics of the particular buttonhole the machine may be designed or. adjusted to sew to meet the requirements of the trade.

Having thus set forth the nature of the invention, what I claim herein is 1. In a buttonhole sewing machine, the combination with the stitch-forming and work-holding devices which are relatively movable to sew about buttonhole, -of an under staycord guide adapted to deliver and laterally position a stay-cord within the range of action of thestitch forniing devices, said guide being movable laterally of the direction of seam-formation during the sewing operation- 2. In a buttonhole sewing machine, the combination with the stitch-forming and workholding devices which are relatively movable to sew about-a buttonhole, of a staycord guide adapted to deliver a stay-cord to the under side of the work and laterally position such stay-cord within'the range of action of the stitch-forming devices, said staycord guide being movable laterally of the direction of seam-formation during the sewing operation, and means for governing the lateral position of said stay-cord guide'as the sewing proceeds around the buttonhole.

8. In a buttonhole sewing machine, the combination with work-holding means and stitch-forming devices including upper and under thread mechanisms, of a stay-cord guide disposed on the same side of the workholding means as the under thread mechanism and adapted to deliver a stay-cord to the under side of the work within the range of action of said stitch-forming devices, and automatic means for moving said stay-cord guide laterally of the direction of seamformation during the sewing operation.

4. A buttonhole sewing machine having, in combination, stitch-forming and workholding devices relatively movable to sew about a buttonhole, a stay-cord guide, a controlling cam surrounding the sewing point, and connections for moving said stay-cord guidelaterally of the direction of seam-formation during the sewing of a buttonhole.

5. A buttonhole sewing machine having, in combination, stitch-forming and workholding devices having relatively travelling and turning movements to sew around a buttonhole, a stay-cord guide, and means actuated by the relative turning movement of the stitch-forming and work-holding devices to shift said stay-cord guide laterally of the line of seam-formation.

6. A buttonhole sewing machine having, in combination, stitch-forming and workholding devices having relative travelling and turning movements to sew around a buttonhole, the stitch-forming devices including under thread mechanism mounted on aturret, a needle-throat member carried by said turret and having a widened stay-cord passageway, and a stay-cord guide carried by said turret and movable relative-to said needle-throat member, said guide determining the lateral position of the stay-cord as 1t leaves said passageway.

7 A buttonhole sewing machine having,

in combination, stitch-forming and work-- holding devices having relative travelling and turning movements to sew around a buttonhole, the stitch-forming devices including under thread mechanism mounted on a turret, a needle-throat member carried by said turret and having a widened stay-cord passageway, a stay-cord guide carried by said turret and movable laterally relative to said needle-throat member, and means for 1n0ving said guide relative to said needle-throat member during the sewing.

8. In a buttonhole sewing machine, stitchforming mechanism including upper and under stitch-forming devices, a turret carrying the under stitch-forming devices, a staycord guide mounted "for movement on and relative to said turret, and a circular cam track surrounding the axis of said turret for moving said stay-cord guide as the turret turns.

9. In a buttonhole sewing machine. stitchforming mechanism including upper and under stitch-forming devices, a turret carrying the under stitch-forming devices, a needle throat member carried by said turret, a stationary circular cam track concentric with the axis of said turret, a lever pivoted on said turret and carrying a cam-follower in engagement With said C2LI11-t1'21Cl(, said lever having a stay-cord guiding aperture disposed adjacent said needle-threat member.

10. In a buttonhole sewing: machine, the combination With the needle-throat member having a widened stay-cord passageway, of an under stay-cord guiding member movable relative to said needle-throat member and-having a stay-cord guiding aperture disposed closely in advance of said needle throat member.

In testimony whereof, I have signed my name to this specification.

EDI VARD B. ALLEN. 

